New details have come to light after an off-duty San Bernardino County sheriff's deputy shot and killed a man moments after he allegedly killed two people outside of a Fontana restaurant on Saturday. 

It happened at around 9:40 p.m. in the Falcon Ridge Town Center, which is located in the 15200 block of Summit Avenue, according to the Fontana Police Department. 

Investigators say that a gunman confronted the victims, a couple who were eating at a sushi restaurant in the shopping center, and shot both. They have been identified as 43-year-old Hector Garduno and 40-year-old Gloria Zamora, both of whom were pronounced dead after they were taken to a nearby hospital.

 On Monday, police also identified the gunman as 45-year-old Tomas Alberto Lizarraga, the estranged husband of Zamora.

"It's tragic. It's a terrible thing," said FPD Officer Steven Reed. "Domestic violence just escalates, escalates. We don't know what their history was, it's usually not the first incident when it's something this tragic."

At the same time that Lizarraga opened fire on the couple, an off-duty San Bernardino County Sheriff's Department deputy was driving by and heard gunshots. 

"He made a U-turn, got out of his vehicle and confronted the suspect, who started to run away," Reed said. 

The deputy opened fire, striking and killing Lizarraga at the scene, according to police. 

Both Fontana police and investigators with SBSD will conduct investigations into the matter.